HELP A MID POWER DUMMY!!

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Bill Gibson

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I have limited experience with mid power rockets so im hoping someone with experience in pad speed/altitude calculations can help me out before I ruin a brand new model!!
I have a 29/38mm ASP Wac Corporal that I wanted to maiden tomorrow at the Bucccaneer Blast here in fla.
We are supposed to have 10-15mph winds all day!
I purchased a pack of F27-4R and F42-4T single use Econojet motors thinking that they would be enough to get my 29 ounce Wac high enough for a safe chute landing, but not so high that I could lose the rocket because of the winds, but after looking more into the data on these motors, im not sure if they are enough to do the job!
If either of these motors is not enough, the only other choice I have is a G77-7/RL which Im not comfortable with as it may send the model up too high.!
I guess I need to learn to use Rocsim for this kind of information but at this moment, if anyone can crunch the numbers to let me know one way or another, I would GREATLY appreciate it!!
MANY THANKS!! Bill
OH! The model weighs 29 oz EMPTY.....no engine, no wadding!
 
Thrust curve is your friend.

Quick & dirty rough calcs using Thrust curve gave me the following:
Depending on your rod length, the F42 will probably work. Take it to about 500'.
G77 will probably take it to 1500'
The F27 probably wont get it safely off the pad.

Really need more info for accurate sim.
 
My Wildman Sport (54mm diameter/29mm motor) weighs 27 oz empty. It flew fine on the F42-4 for its maiden flight, from a 4 ft rail it was simmed at around 45 ft/s off the rail. Didn't go very high at all, no altimeter so don't know how high exactly but it was low. A G53-7 sent it to around 1100. In those winds it would still be a relatively easy recovery either way. If you can use a longer rail, it will raise your speed at rail clearance a bit and help out. If someone will let you borrow a chute release and you have room, that would help too.
 
I have limited experience with mid power rockets so im hoping someone with experience in pad speed/altitude calculations can help me out before I ruin a brand new model!!
I have a 29/38mm ASP Wac Corporal that I wanted to maiden tomorrow at the Bucccaneer Blast here in fla.
We are supposed to have 10-15mph winds all day!
I purchased a pack of F27-4R and F42-4T single use Econojet motors thinking that they would be enough to get my 29 ounce Wac high enough for a safe chute landing, but not so high that I could lose the rocket because of the winds, but after looking more into the data on these motors, im not sure if they are enough to do the job!
If either of these motors is not enough, the only other choice I have is a G77-7/RL which Im not comfortable with as it may send the model up too high.!
I guess I need to learn to use Rocsim for this kind of information but at this moment, if anyone can crunch the numbers to let me know one way or another, I would GREATLY appreciate it!!
MANY THANKS!! Bill
OH! The model weighs 29 oz EMPTY.....no engine, no wadding!

The F42 should work fine. My 5 second Thrustcurve sim echoes what others have already said:

MotorWeightLaunchVelocityAccelAltitudeTimeDelay
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AeroTech F4231.7oz15m/s49m/s6.8G157m6.1s5s
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AeroTech F5032.0oz16m/s64m/s7.2G232m7.3s6s
status_ok.png
AeroTech G7432.1oz18m/s83m/s9.4G346m8.7s8s
status_ok.png
AeroTech G14232.5oz26m/s86m/s18.3G348m8.4s8s
status_ok.png

AeroTech G4033.3oz15m/s83m/s6.9G408m9.7s7s
W
AeroTech G35
32.5oz
15m/s82m/s
7.4G
428m10.0s
7s
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AeroTech G7733.3oz17m/s97m/s9.9G449m9.8s9s
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AeroTech G7933.4oz16m/s96m/s8.0G470m10.2s8s
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AeroTech G7533.6oz18m/s108m/s9.8G567m10.9s9s
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AeroTech G7833.4oz19m/s112m/s10.1G593m11.1s9s
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AeroTech G12533.4oz23m/s123m/s16.0G630m11.2s10s
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AeroTech G8033.5oz20m/s118m/s10.3G643m11.5s10s
status_ok.png

AeroTech H5535.6oz18m/s137m/s8.4G900m13.6s11s
status_ok.png

AeroTech H11536.2oz21m/s159m/s11.6G960m13.7s12s
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AeroTech H7036.9oz21m/s170m/s11.3G1,188m15.2s12s
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AeroTech H18236.3oz25m/s202m/s19.0G1,245m15.0s14s
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AeroTech H13536.5oz23m/s194m/s14.3G1,309m15.6s14s
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AeroTech H19535.9oz30m/s222m/s24.4G1,387m15.5s14s
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AeroTech I20540.1oz28m/s280m/s31.6G1,923m17.7s16s
 
BTW, if you don't want to splurge $100+ for a copy of Rocksim, there's an open source rocketry simulator known as openrocket that works almost identically. You can download it from openrocket.info. It's a great tool, something that every rocketeer should learn how to use.
 
judging from the last 2 days Bill, fly early is your friend. :rolleyes:
I gotta go get 2 new tires on the Yeep before I can travel- see ya late am :wink:
 
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